HDMI Audio not working on Sapphire 6870 on Mountain Lion 10.8.4

[shlokpatel]

Here you go. Its very weird because I have to use DSDT=null when booting using hd4000 which is weird as the dsdt is fine (same one I created before)

 

[toleda]

Here you go. Its very weird because I have to use DSDT=null when booting using hd4000 which is weird as the dsdt is fine (same one I created before)

Different BIOS setting with integrated or discrete graphics.

 

[shlokpatel]

OK Thanks, do you know how to solve the problem?

 

[shlokpatel]

HDMI audio doesn't seem to be working with HD4000. I created another dsdt which was just a clean dsdt with clean compile patch and a3 patch however I made it when booted into hd4000 and I can boot without dsdt=null however hdmi audio doesn't work. HD4000 seems to be fully recognised as I see Intel HD Graphics 4000 512 MB in system info however hdmi audio doesn't work and I cannot select 1080p resolution (always had this problem). I have uploaded the dsdt, ioreg and a picture of what happens when I select 1080p resolution. Even for other resolutions the graphic mucks up. Only default seems to look normal.

 

[toleda]

HDMI audio doesn't seem to be working with HD4000.
I cannot select 1080p resolution (always had this problem).

The 03 framebuffer does not have an HDMI connector; no HDMI audio. Use the 0a framebuffer. Set MultiBeast/1080p.

 

[shlokpatel]

How can I change the framebuffer for HD4000? Sorry if its a stupid question

 

[toleda]

How can I change the framebuffer for HD4000?

The A1 and A3 edits use 0a. Did you change it?

Should be:

                        "AAPL,ig-platform-id", 
                        Buffer (0x04)
                        {
                             0x0A, 0x00, 0x66, 0x01
                        },

 

[shlokpatel]

OK Thanks, now HDMI audio working however I still cannot get 1080p to work even after applying 1080p. Not having 1080p is the only reason I do not use hd4000 so if I could fix it, I wouldn't have to hassle with 6870

 

[shlokpatel]

I just realised that in system info it shows HD400 768MB. Shouldn't it be 512MB? I've uploaded the dsdt and ioreg. HDMI audio works.

---------------- EDIT ----------------

Fixed the 1080p problem!

Solution
- Before changing to 1080p, slide the underscan slider all the way to the right and then change. Seems to be problems when using tv where overscan is enabled.

 

[toleda]

I just realised that in system info it shows HD400 768MB. Shouldn't it be 512MB?

10.8.4 feature.